Who does the Injun swear vengeance on?

Injun Joe swore he'd get revenge on the doctor. 

‘Yes, and you done more than that,’ said Injun Joe, approaching the doctor, who was now standing. ‘Five years ago you drove me away from your father’s kitchen one night, when I come to ask for something to eat, and you said I warn’t there for any good; and when I swore I’d get even with you if it took a hundred years, your father had me jailed for a vagrant. Did you think I’d forget? The Injun blood ain’t in me for nothing. And now I’ve GOT you, and you got to SETTLE, you know!’